Resumen de Characterization of the inessential endomorphisms in the category of Abelian groups

Hassane Essannouni, S. Abdelalim

• An endomorphism f of an Abelian group A is said to be inessential (in the category of Abelian groups) if it can be extended to an endomorphism of any Abelian group which contains A as a subgroup. In this paper we show that f is as above if and only if (f − v idA)(A) is contained in the maximal divisible subgroup of A for some v ∈ Z.